Acute pancreatitis (AP) is the most frequent pancreatic disorder in children and abdominal ultrasound (AUS) is very helpful in the clinical management. Even though several agents have been implicated in the etiology of AP, influenza virus A (IVA) is exceptional. We report the case of a 6-year-old girl who presented with generalized abdominal pain and flu-like symptoms. Blood tests and AUS revealed typical findings of AP and a nasopharyngeal aspirate was positive for IVA. Twenty-four hours later, the patient developed signs of acute appendicitis, which was also confirmed by AUS. This case highlights the importance of AUS in the management of acute abdominal conditions in children, including reactive entities such as appendicitis, as well as the need to consider IVA as a potential causal agent of AP.